You seem to be able to add as many en spaces (and so presumably em spaces) as you like (while only one ordinary space is allowed), but if you are writing more than two lines and not using a monospaced font it may not be a very good solution._________________OpenOffice 4.0.0 and LibreOffice 4.x.x on Fedora 20, Ubuntu 13.10, Windows 8.1 Preview (Triple Boot)